WO2006001255A1 - Tire wear detection system and pneumatic tire - Google Patents

Abstract

A tire wear detection system comprises a detecting means (70) for detecting the acceleration which acts on a slip sign (40) installed in a groove of the tread of a pneumatic tire (10), and a wear judgement means (82) for judging that the tire has worn out on the basis of the acceleration detected by the detection means (70).

Description

 Specification

 Tire wear detection system and pneumatic tire

 Technical field

 TECHNICAL FIELD [0001] The present invention relates to a tire wear detection system and a pneumatic tire for detecting a tire wear state.

 Background art

 [0002] Conventionally, if there is too little remaining groove on the tire surface, it is natural that legal problems will occur.

1S had a major impact on driving safety. In managing such tire wear, the driver or vehicle operation manager must visually check the tread pattern groove depth or the appearance of slip signs on the tire. The tires are inspected for wear, and when the tread reaches wear, it is replaced with a new tire.

 [0003] In order to make the slip sign stand out, a technique for coloring the slip sign, embedding a bow, and generating abnormal noise is disclosed (see, for example, Japanese Utility Model Publication No. 56-120901). ).

 [0004] In addition, when visually checking the wear state of a tire, if a driver or the like neglects to check or mistakes the check method, the tire will be left even if it reaches the wear limit. It is not preferable. For this reason, when a light reflecting member having a light reflecting surface is embedded in the inside of the tread and the tire is worn, the irradiation light from the outside is reflected by the light reflecting surface and receives the light, thereby causing the tire to wear. Is disclosed (for example, see Japanese Patent Publication No. 11 170819).

 However, in the conventional technology shown in Patent Document 1, the appearance of the tire is damaged, and the road surface is damaged when the tire is worn to embed the bottle, and the damage to the tire is accelerated. is there.

[0005] In addition, in the prior art shown in Patent Document 2, since the reflected light is detected to check the degree of wear, the reflecting surface is exposed when the reflecting surface becomes dirty or the light receiving surface becomes dirty. However, since the reflected light cannot be detected, it may not be recognized even if the tire exceeds the wear limit. [0006] In view of the above problems, an object of the present invention is to provide a tire wear detection system and a pneumatic tire that are highly reliable for tire wear detection without damaging the tire or road surface.

 Disclosure of the invention

 [0007] A first feature of the present invention is based on detection means for detecting an acceleration applied to a slip line disposed in a groove portion of a tread portion of a pneumatic tire, and on the basis of the acceleration detected by the detection means. The gist of the present invention is a tire wear detection system including a wear judgment means for judging that the tire is worn.

 [0008] According to the tire wear detection system according to the first feature, since the acceleration applied to the slip sign is detected, highly reliable wear detection can be performed. In addition, since the tire surface is not heated, the tire and the road surface are not damaged. In addition, it is usually necessary to apply a new force to the tread part to use the slip sign that is installed on the tire!

 [0009] The second feature of the present invention is that the physical quantity corresponding to the slip sign disposed in the groove portion of the tread portion of the pneumatic tire contacting the road surface is detected, and the physical quantity is based on the physical quantity. The gist of the present invention is that it is a tire wear detection system provided with wear judging means for judging that the tire is worn.

 [0010] A third feature of the present invention is summarized as a pneumatic tire including a detecting unit that detects an acceleration applied to a slip sign disposed in a groove portion of a tread portion of the pneumatic tire.

 [0011] A fourth feature of the present invention is a pneumatic tire including a detecting unit that detects a physical quantity corresponding to a slip sign disposed in a groove portion of a tread portion of the pneumatic tire contacting the road surface. Is the gist.

 Brief Description of Drawings

FIG. 1 is a perspective view of a pneumatic tire according to this embodiment.

 FIG. 2 is a cross-sectional view along the tire rotation axis of the pneumatic tire according to the present embodiment.

 FIG. 3 is an example of a detection signal of the acceleration sensor according to the present embodiment.

FIG. 4 is a diagram illustrating a tire wear detection system according to the present embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

 Next, the present invention will be described in detail.

[0014] (Pneumatic tire)

 First, an embodiment of the pneumatic tire of the present invention will be described with reference to FIGS. 1 and 2.

 As shown in FIG. 1, a tread pattern composed of convex portions 20 and groove portions 30 is formed on the surface of the tread portion of the pneumatic tire 10. In this groove portion 30, slip signs 40 are arranged at regular intervals.

 [0016] The slip sign 40 has a height of 1.6 mm from the bottom of the groove, and indicates the lowest line of the remaining groove as worn by law. In addition, an arrow indicating the position of the slip sign 40 (triangle mark in FIG. 1) is displayed on the side portion of the tire, and the arrow and the slip sign 40 are normally arranged at six locations on the tire circumference. .

 In the pneumatic tire 10 according to the present embodiment, as shown in FIG. 2 (a), the convex surface 21 contacts the road surface 100 and rolls. A slip sign 40 is provided on the groove surface 31, and a carcass 50 that functions as a strength member for maintaining the pressure of air filled in the tire is provided on the inner side in the tire radial direction of the tread portion, and a rubber layer inside the tire. One inner liner, 60, etc. is configured. The other structures are conventionally known structures and are not particularly limited.

 [0018] The acceleration applied to the slip sign 40 disposed in the groove portion of the tread portion of the pneumatic tire 10 is detected on the inner side in the tire radial direction of the slip sign 40 (the surface of the inner liner 60 in the figure). An acceleration sensor 70 (detection means) is provided.

 The acceleration sensor 70 detects vibration and displacement of the slip sign 40 and detects acceleration applied to the slip sign 40. As the acceleration sensor 70, for example, a piezoelectric acceleration sensor using a piezoelectric ceramic, a resistance (piezo-resistive) acceleration sensor, or the like is used. Piezoelectric accelerometers do not maintain steady acceleration and detect only the change in acceleration, but resistance accelerometers also maintain steady acceleration, so the rotational speed can be estimated, and even if the speed changes, the steady acceleration And the peak value of acceleration can be detected.

[0020] When the tire is worn, the slip sign 40 contacts the road surface 100 as shown in FIG. 2 (b). At this time, the acceleration sensor 70 has a large gravity (acceleration) as compared with the state of FIG. Degree).

 Note that this acceleration is an acceleration in the vertical direction.

 FIG. 3 shows the gravity (acceleration) detected by the acceleration sensor 70. Fig. 3 (a) shows a new state, and Fig. 3 (b) shows a state where wear has progressed.

 [0023] In Fig. 3 (a), G1 is the acceleration when the tire tread near the slip sign 40 is grounded when the tire is new, and G2 is the ground when the tire tread near the slip sign 40 is grounded when the tire is new. Acceleration when not. G / in Fig. 3 (b) is the acceleration when the tire tread near the slip sign 40 is in contact with the ground, and G2 ^ until the tire tread near the slip sign 40 is in contact with the ground. The acceleration is G2 ^.

 [0024] While the tire makes one rotation, the acceleration sensor 40 detects G1 and G2 or G / and G2 '. The difference between G1 and G2 is small when the tire is new, but as wear progresses, greater acceleration is applied at the time of ground contact, and the difference is greater.

 [0025] It should be noted that in G2 and the same figure, the average value of acceleration other than the time of grounding is not limited to this, and may be a single point of acceleration other than the time of grounding.

 [0026] A method for determining that the tire is worn will be described in detail later.

[0027] Although the detection means is described as the acceleration sensor 70 for detecting the acceleration applied to the slip sign 40, the detection means is not limited to this, and the detection means is not limited to the slip line 40 on the road surface 100. It is a variety of sensors that detect physical quantities corresponding to contact.

 [0028] (Tire wear detection system)

 As shown in FIG. 4, the tire wear detection system according to the present embodiment is mounted on one automobile, and includes acceleration sensors (detection means) 70a, 70b, 70c, 70d, ECU 80, meter display unit 90, Is provided.

[0029] The acceleration sensors 70a, 70b, 70c, and 70d detect acceleration applied to the slip sign 40 disposed in the groove portion of the tread portion of the pneumatic tire 10, and are disposed in each tire of the automobile. . In FIG. 4, one acceleration sensor is disposed per tire. Of course, a plurality of acceleration sensors may be disposed in one tire. or, The acceleration sensors 70a, 70b, 70c, and 70d output a signal including the detected value to the ECU 80.

 [0030] The ECU (electronic control unit or engine 'control unit') 80 includes a control unit 81, a wear determination unit 82 (wear determination unit), and a storage unit 83 (storage unit). Has been.

 [0031] The wear determination unit 82 includes acceleration sensors 70a, 70b, 70c as means for detecting a physical quantity,

Based on the magnitude of acceleration detected by 70d, it is determined that the tire is worn.

[0032] Specifically, wear determination unit 82 receives signals output from acceleration sensors 70a, 70b, 70c, and 70d. The wear determination unit 82 determines that the tire has been worn when a predetermined acceleration is detected by the acceleration sensor 70.

[0033] At this time, if the wheel speed is detected by a wheel speed sensor (not shown) or the like, the time per one rotation of the tire can be determined, and the acceleration sensor output value can be easily determined. Specifically, it becomes easier to detect the values of G2 and G2 'shown below.

[0034] Further, when a reference acceleration serving as a reference is stored in the storage unit 83 to be described later, and the difference between the reference acceleration and the acceleration detected by the acceleration sensors 70a, 70b, 70c, 70d is equal to or greater than a certain value. The wear determining unit 82 may determine that the tire is worn.

[0035] Here, the reference acceleration may be an acceleration when a tire is new, or an acceleration sensor.

It may be an average of accelerations detected within a predetermined time by 70a, 70b, 70c, and 70d.

 [0036] Further, when K is a predetermined value greater than 1, the acceleration force detected by the acceleration sensors 70a, 70b, 70c, 70d is represented by the following formula (I)

 G1VG2'≥kGl / G2--'Formula (I)

 If the condition is satisfied, the wear determination unit 82 may determine that the tire is worn.

[0037] The storage unit 83 is a storage medium that stores a program for causing the wear determination unit 82 to execute, a reference acceleration, Equation (1), a numerical value selected in advance such as K, and the like. Examples of the storage medium include RAM. According to such a recording medium, it is possible to easily store, transport, sell, etc. a program.

[0038] Based on information from each sensor (instruments), the control unit 81 determines the fuel injection amount and the injection amount of the engine. Control each part of the car, such as determining the time.

 [0039] The vehicle body ECU 80 can use speed information by a vehicle speed sensor.

 [0040] The output signals to the ECU 90 such as the force sensors 70a, 70b, 70c, and 70d may be transmitted wirelessly using a wireless LAN or the like.

 [0041] The meter display unit 90 notifies by displaying the analysis result by the ECU 80 so as to be visible. The display on the meter display unit 90 can notify that the tire is being worn. For this reason, it is possible to easily and instantly recognize that tire wear has occurred on the driver.

 [0042] The meter display unit 90 displays the force indicating the speedometer, the remaining amount of gasoline, and the like, and also displays that the ECU 80 detects wear. In Fig. 4, turn on the position of the tire where wear has been detected.

 [0043] It should be noted that the location where the wear is detected is not limited to the meter display unit 90, and a different display device may be provided. In addition, when wear is detected on the display, an alarm may be sounded to notify that wear has been detected by sound.

 [0044] (Function and effect)

 According to the pneumatic tire 10 and the tire wear detection system according to the present embodiment, the tire wear detection system force the acceleration sensor 70 for detecting the acceleration applied to the slip line 40 disposed in the groove portion of the tread portion of the pneumatic tire 10 and And a wear determination unit 82 that determines that the tire has been worn based on the acceleration detected by the acceleration sensor 70. Therefore, by detecting the acceleration applied to the slip sign 40, highly reliable wear detection is possible. It can be performed. Moreover, since no force is applied to the tire surface, the appearance without damaging the tire and the road surface is not different from the conventional tire.

 [0045] Furthermore, since the slip sign 40 provided on the tire is normally used, it is not necessary to perform a new process on the tread portion.

Note that a sensor that detects a physical quantity may be used instead of the acceleration sensor 70 that detects acceleration. Even in this case, the sensor can detect the physical quantity applied to the slip sign 40 so that the wear detection can be performed with high reliability. In addition, since the tire surface is not subjected to caloe, the appearance that does not damage the tire and road surface is different from conventional tires. There is no change.

 [0047] Further, a storage unit 83 for storing a reference acceleration serving as a reference in the pneumatic tire 10 is further provided, and the wear determination unit 82 has a constant difference between the reference acceleration and the calorie speed detected by the acceleration sensor 70. In the above case, it is determined that the tire is worn, so wear detection can be performed with high reliability.

 [0048] Further, since the reference acceleration is the acceleration when the tire is new, it can be easily measured.

 [0049] Furthermore, since the reference acceleration is the average of the accelerations detected by the acceleration sensor 70 within a predetermined time, wear detection with higher reliability can be performed.

Further, the acceleration force detected by the wear sensor 82 by the acceleration sensor 70 is represented by the following formula (I)

 G1VG2'≥kGl / G2--'Formula (I)

 When the condition is satisfied, it is determined that the tire is worn, so that highly reliable wear detection can be performed.

 [0051] Further, since the acceleration is the acceleration in the vertical direction, it can be easily measured.

 [0052] Further, since the acceleration sensor 70 is disposed on the inner side in the tire radial direction of the slip sign 40, the acceleration applied to the slip sign 40 that has been conventionally arranged can be detected.

 [0053] Further, since the acceleration sensor 70 is disposed on the surface of the inner liner 60 of the pneumatic tire 10, the acceleration sensor 70 can be attached after the conventional manufacturing process. Can avoid complications.

 In addition, according to the pneumatic tire 10 and the tire wear detection system according to the present embodiment, the pneumatic tire 10 force detects the acceleration applied to the slip sign 40 disposed in the groove portion of the tread portion of the pneumatic tire 10. Since the acceleration sensor 70 is provided, it is possible to detect wear with high reliability by detecting the acceleration applied to the slip sign 40.

 It should be noted that a sensor that detects a physical quantity may be used instead of the acceleration sensor 70 that detects the 10-force acceleration of the pneumatic tire. Even in this case, the sensor can detect wear with high reliability by detecting the physical quantity applied to the slip sign 40.

Industrial applicability As described above, the pneumatic tire according to the present invention can be suitably used as a vehicle tire because it can detect the wear of the tire without damaging the tire or the road surface.

Claims

The scope of the claims  [1] Detection means (70) for detecting an acceleration applied to the slip sign (40) disposed in the groove portion of the tread portion of the pneumatic tire (10),  A tire wear detection system comprising wear determination means (82) for determining that the tire is worn based on the acceleration detected by the detection means (70). [2] Storage means (83) for storing a reference acceleration serving as a reference in the pneumatic tire (10) is further provided,  The wear determination means (82) determines that the tire is worn when a difference between the reference acceleration and the acceleration detected by the detection means (70) is a predetermined value or more. The tire wear detection system according to 1.  3. The tire wear detection system according to claim 2, wherein the reference acceleration is an acceleration when a tire is new.  4. The tire wear detection system according to claim 2, wherein the reference acceleration is an average of accelerations detected within a predetermined time by the detection means (70).  [5] When the tire is new, the tire tread near the slip sign (40) is grounded, and when the tire is new, the acceleration is G1, and when the tire is new, the tire tread near the slip sign (40) is grounded. The acceleration at the time is G2, the tire tread near the slip sign (40) is grounded! /, The acceleration at the time is G Γ, and the tire tread near the slip sign (40) is in contact. If the acceleration at the time is G2 ′ and K is greater than 1 and a predetermined value, the wear determination means (82) is detected by the detection means (70). The acceleration is expressed by the following formula (I)  G1VG2'≥kGl / G2--'Formula (I)  2. The tire wear detection system according to claim 1, wherein if the condition is satisfied, it is determined that the tire is worn.  6. The acceleration according to any one of claims 1 to 5, wherein the acceleration is a vertical acceleration. V, slippage or tire wear detection system according to item 1. [7] The tire wear according to any one of claims 1 to 6, wherein the detection means (70) is disposed on an inner side in the tire radial direction of the slip sign (40). Detection system Mu.  [8] The detection means (70) according to any one of claims 1 to 7, wherein the detection means (70) is disposed on a surface of an inner liner (60) of the pneumatic tire (10). Tire wear detection system.  [9] The slip sign (40) placed in the groove of the tread of the pneumatic tire (10) is the road surface (100 Detection means (70) for detecting a physical quantity corresponding to contact with  A tire wear detection system comprising: a wear determination means (82) for determining that the tire is worn based on the magnitude of the physical quantity. [10] A pneumatic tire comprising a detecting means (70) for detecting an acceleration applied to a slip sign (40) disposed in a groove portion of a tread portion of the pneumatic tire (10). [11] The slip sign (40) placed in the groove of the tread of the pneumatic tire (10) is the road surface (100 A pneumatic tire characterized by comprising a detecting means for detecting a physical quantity corresponding to the contact with ().